1. Field of the Invention
The present invention relates to apparatus for detecting flaws such as checks, chippings, cracks or the like on the head of a bottle, and is directed more particularly to apparatus for detecting flaws such as cracks or the like on the lip or edge at the mouth or the head portion of a bottle for beverage, refreshments, beer and so on.
2. Description of the Prior Art
As well known, if a bottle with such a flaw as a check, chipping, crack or the like on its mouth is filled with refreshments, beverage, beer or the like and then to be sealed by a crown cap, leakage or other troubles may occur when or after the bottle is crowned or capped. Therefore, it is necessary to detect certain flaws immediately before the bottle is filled with its contents and capped.
In the prior art, the detection of flaws on the bottle mouth is carried out by the naked or unaided eye. This prior art detection by the naked eye requires rather long continued concentration for an observer and is not really effective due to human error and fatigue.
Other methods proposed in the art to detect flaws on a bottle mouth utilize light from a plurality of light sources which is irradiated on the bottle mouth and the reflected light on the bottle mouth is received by a television camera or photo-cell arrays. Such methods, however, are impractical because it is rather difficult to irradiate the bottle mouth or head of the bottle to be tested uniformly with light from a number of light sources and shades of bright and dark are likely appear on the bottle head which deteriorate the flaw detection results.
An object of the invention is to provide apparatus for detecting a flaw such as a check, chipping, crack or the like on the head or mouth of a bottle accurately and automatically.
Another object of the invention is to provide an apparatus for detecting a flaw such as check, chipping, crack or the like on a bottle mouth in which a number of optical fiber bundles are located between a single light source and the bottle mouth, whose flaws are to be detected, to transmit the light therethrough from the single light source to the bottle mouth, and the light reflected on the bottle mouth is received by a sensor such as a television camera.
According to an aspect of the present invention, there is provided a flaw detecting apparatus which comprises a light source, a number of optical fiber bundles each having one end facing the light source for transmitting light therefrom to the other ends. A light projecting body having a center bore and a number of apertures formed through the body is provided so that, the center bore has an inner diameter approximately equal to or larger than the outer diameter of a head of a bottle whose flaw or the like is detected. The apertures are so formed that they each lie on a tangential line to one of a number of points lying in a circle on the center bore, which substantially corresponds to the peripheral edge of the head of the bottle. The aperatures are inclined upwards and outwards with respect to the lower portion of the center bore, and their inner ends communicate with the center bore at the lower portion thereof. An optical fiber bundle is inserted into the aperture to a position near the center bore so as to irradiate the head of the bottle. A sensing device for picking up an image of the head of the bottle is provided in alignment with the center bore.
Other objects, features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings through which the like references designate the same elements and parts.